I've read all of them only once. I got into some other series and haven't been able to get back to rereading them again. Also, to make it clear, the other series is not Twilight, I'd rather die. LMAO!
As a whole, I've probably read through the entire series at least 20 times. When it comes to the different books, there are some I prefer 更多 than others. I've re-read the Goblet of 火, 消防 and Half Blood Prince about two and half dozen times, with the Deathly Hallows coming in at a close 秒 although I tend to skip over the ending. I really don't like the fifth one all that much. I've probably only read it five 或者 six times. I'm not too fond of the third one either. The other two are a kind of normal number, like ten 或者 eleven.
I'm on the last one. But I'm also 阅读 the 4th one. I have not read the first one. I started 阅读 the 6th after watching the 5th in cinemas. I found it 更多 difficult to read the children hard cover 图书 than the adult pocket version. I think the first book looks really easy to read, since it's only 350 pages(not so many either). Well, I loved the 6th one and It was really pity for the movie with Snape. He was so little in it, but that's of the point here.
I'd say 6 times. 7th is still running, I'm on 4th book right now. But if I keep going like this, I'll have to buy new copies, they are so weather beaten. 你 know, I keep dragging them to the 海滩 或者 onto the ship and everywhere when we go on holiday.